Semiconductor device

ABSTRACT

A semiconductor device includes a substrate, a plurality of pads disposed over the substrate, and a solder mask disposed over the substrate. The substrate includes a pair of first edges parallel to each other, a pair of second edges orthogonal to the pair of first edges, and a center point. The solder mask includes four recess portions exposing an entire top surface and sidewalls of four of the pads in four corners of the regular array, and a plurality of second recess portions exposing a portion of a top surface of other pads in the regular array. A pad size of the four pads in the four corners of the regular array exposed through the first recess portions and a pad size of the other pads exposed through the second recess portions are the same.

PRIORITY CLAIM AND CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No. 15/823,051, entitled “SEMICONDUCTOR DEVICE” filed on Nov. 27, 2017, which is a continuation of U.S. patent application Ser. No. 14/082,714, entitled “SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF” filed on Nov. 18, 2013; each of these applications are incorporated herein by reference in their entireties.

FIELD

The disclosure relates to a semiconductor device and a method of manufacturing a semiconductor device.

BACKGROUND

Electronic equipments involving numbers of semiconductor devices are indispensable from our daily life. With the advancement of electronic technology, the electronic equipment has becomes smaller in size and has to execute and perform more and more complicated and multiple functions. Thus, the electronic equipment becomes more compact involving more numbers of electronic components, and becomes more complex in structure involving high density of input/output (I/O) terminals within such a small area.

A wafer level packaging (WLP) technology has been gaining in popularity. This technology provides a wafer level manufacturing of the semiconductor device with high functions and performances while small size of the semiconductor device. During manufacturing of the semiconductor device, a surface mounting technology (SMT) is employed for miniaturizing the semiconductor device. The semiconductor device includes a substrate mounting on another substrate, so that a pad of the substrate is bonded and electrically connected with a pad of another substrate through a solder ball.

The pads of the substrate are formed on a top surface of the substrate by various methods. However, the pads formed by different methods would provide different reliability with respect to drop test, thermal cycling, bending or etc. For example, some pads would be able to withstand a high stress level and thus cracks would not be developed easily, while some pads would be able to withstand a high temperature and thus delamination from the substrate is minimized.

As such, there is a continuous demand on improving the configuration of the pads on the substrate and manufacturing operations of the pads to optimize reliability of the pads and solve the above deficiencies.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1A is a schematic view of a semiconductor device with a non-solder mask defined (NSMD) pad in accordance with some embodiments of the present disclosure.

FIG. 1B is a top view of a semiconductor device with a NSMD pad in accordance with some embodiments of the present disclosure.

FIG. 2A is a schematic view of a semiconductor device with a solder mask defined (SMD) pad in accordance with some embodiments of the present disclosure.

FIG. 2B is a top view of a semiconductor device with a SMD pad in accordance with some embodiments of the present disclosure.

FIG. 3A is a schematic view of a semiconductor device with a NSMD pad and a SMD pad in accordance with some embodiments of the present disclosure.

FIG. 3B is a top view of a semiconductor device with a NSMD pad and a SMD pad in accordance with some embodiments of the present disclosure.

FIG. 4A is a top view of a semiconductor device with a NSMD pad at a corner in accordance with some embodiments of the present disclosure.

FIG. 4B is a top view of a semiconductor device with a NSMD pad adjacent to a corner in accordance with some embodiments of the present disclosure.

FIG. 4C is a top view of a semiconductor device with a NSMD pad adjacent to a void region in accordance with some embodiments of the present disclosure.

FIG. 5 is a flow diagram of a method of manufacturing a semiconductor device in accordance with some embodiments of the present disclosure.

FIG. 5A is a schematic view of a semiconductor device with a first substrate in accordance with some embodiments of the present disclosure.

FIG. 5B is a schematic view of a semiconductor device with several pads in accordance with some embodiments of the present disclosure.

FIG. 5C is a schematic view of a semiconductor device with a solder mask in accordance with some embodiments of the present disclosure.

FIG. 5D is a top view of a semiconductor device with a NSMD pad at a corner in accordance with some embodiments of the present disclosure.

FIG. 5E is a top view of a semiconductor device with a NSMD pad adjacent to a corner in accordance with some embodiments of the present disclosure.

FIG. 5F is a top view of a semiconductor device with a NSMD pad adjacent to a corner in accordance with some embodiments of the present disclosure.

FIG. 5G is a top view of a semiconductor device with a NSMD pad outside a circle in accordance with some embodiments of the present disclosure.

FIG. 5H is a top view of a semiconductor device with a NSMD pad outside a circle in accordance with some embodiments of the present disclosure.

FIG. 5I is a schematic view of a semiconductor device with a NSMD pad and a SMD pad in accordance with some embodiments of the present disclosure.

FIG. 5J is a schematic view of a semiconductor device with a second substrate in accordance with some embodiments of the present disclosure.

FIG. 5K is a schematic view of a semiconductor device with a first substrate and a second substrate in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

In the surface mount technology (SMT), the semiconductor device includes at least two substrates. One of the substrates is stacked on another one of the substrates by attaching a pad of the substrate with a pad of another substrate through a conductive bump such as a solder joint or a solder bump. The pad of the substrate is formed by sputtering or electroplating a conductive material on the substrate, so that the pad conducts an electricity between a circuitry of the substrate and a circuitry of another substrate external to the substrate. The pad of the substrate is then covered by a soldering material in order to selectively expose a top surface of the pad. The pad could be exposed by various methods which define an area on the top surface of the pad for receiving the bump. The exposed surface of the pad is then attached with the bump.

However, the above configuration of the pad on the substrate have some issues such as reduction of adhesion between the pad and the substrate, poor performance in mechanical testing such as board bending or drop test, stress concentration on a periphery of the pad, poor reliability in a board level temperature cycling, etc. As the pad formed and exposed by different methods would have different issues, ultimately the substrate would overall have low reliability and poor functional performance.

The manufacturing and use of the embodiments of the present invention are discussed in details below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. It is to be understood that the following disclosure provides many different embodiments or examples for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting.

Embodiments, or examples, illustrated in the drawings are disclosed below using specific language. It will nevertheless be understood that the embodiments and examples are not intended to be limiting. Any alterations and modifications in the disclosed embodiments, and any further applications of the principles disclosed in this document are contemplated as would normally occur to one of ordinary skill in the pertinent art.

Further, it is understood that several processing steps and/or features of a device may be only briefly described. Also, additional processing steps and/or features can be added, and certain of the following processing steps and/or features can be removed or changed while still implementing the claims. Thus, the following description should be understood to represent examples only, and are not intended to suggest that one or more steps or features is required.

In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

In the present disclosure, a semiconductor device with an improved configuration is disclosed. The semiconductor device includes a substrate and several pads on the substrate which are in a combination of solder mask defined (SMD) pads and non-solder mask defined (NSMD) pads, such that disadvantages of the SMD pads and the NSMD pads are offset and thus the substrate as a whole possesses advantages contributed from the SMD pads and the NSMD pads, such as high reliability with respect to the board level temperature cycle, good performance in drop test, reduction in number of stress concentration point, etc.

FIG. 1A is an embodiment of a semiconductor device 100. The semiconductor device 100 includes a substrate 101. In some embodiments, the substrate 101 is a circuit board including a silicon substrate for carrying a circuitry within the silicon substrate and supporting several semiconductor components connected to the circuitry. The silicon substrate includes several conductive layers and several dielectric layers. The conductive layers include some conductive traces for electrically connecting several semiconductor components on the silicon substrate. The dielectric layers are configured for insulation between the conductive traces. In some embodiments, the circuit board is a printed circuit board (PCB) including some integrated circuits (IC) for electrical connection of the semiconductor components thereon. In some embodiments, the substrate 101 is in a strip shape.

In some embodiments, the semiconductor device 100 includes a pad 102 disposed on a surface 101 a of the substrate 101. The pad 102 is extended horizontally along the surface 101 a. In some embodiments, the pad 102 is an under bump metallurgy (UBM) pad for receiving a conductive bump including copper, tin, lead or etc. The UBM pad is a solderable surface which is exposed for receiving the bump and electrically connecting the pad 102 with a circuitry internal to the substrate 101. The pad 102 is bonded with the bump after heat treatment such as reflow.

In some embodiments, the pad 102 is disposed on the surface 101 a by various methods such as electroplating, sputtering, etc. In some embodiments, the pad 102 includes a conductive material such as gold, silver, copper, nickel, tungsten, aluminum, and/or alloys thereof.

In some embodiments, the semiconductor device 100 includes a solder mask 103 disposed over the surface 101 a of the substrate 101. In some embodiments, the solder mask 103 is spaced from the pad 102. The solder mask 103 surrounds the pad 102. There is a gap 104 between the solder mask 103 and the pad 102. The solder mask 103 is not contacted with the pad 102 and is not covered the pad. In some embodiments, a top surface 103 a of the solder mask 103 is at a level above a top surface 102 a of the pad 102.

In some embodiments, the solder mask 103 includes a polymeric material such as liquid epoxy, polyepoxide or etc. In some embodiments, the solder mask 103 is disposed on the surface 101 a of the substrate 101 by silk screening, spraying, etc.

In some embodiments, the solder mask 103 includes a first recessed portion 103 b. The first recessed portion 103 b surrounds the pad 102, that the pad 102 is disposed within the first recessed portion 103 b of the solder mask 103. In some embodiments, the first recessed portion 103 b is extended from the top surface 103 a of the solder mask 103 to the top surface 101 a of the substrate 101.

In some embodiments, a sidewall of the first recessed portion 103 b is disposed away from the pad 102. In some embodiments, the first recessed portion 103 b is configured for exposing the top surface 102 a and a peripheral portion 102 b of the pad 102 to receive a bump.

In some embodiments, the pad 102 is a non-solder mask defined (NSMD) pad. The NSMD pad 102 is disposed within the first recessed portion 103 b and is spaced from the solder mask 103. The NSMD pad 102 is isolated from the solder mask 103. The top surface 102 a and the peripheral portion 102 b of the pad 102 are not covered by the solder mask 103. The top surface 102 a of the NSMD pad 102 is absent from the solder mask 103. An area of the NSMD pad 102 for receiving the bump is not dependent on a size of the first recessed portion 103 b. The first recessed portion 103 b is larger than the NSMD pad 102.

FIG. 1B is a top view of an embodiment of a semiconductor device 100 as in FIG. 1A. The semiconductor device 100 includes a substrate 101, a pad 102 and a solder mask 103. In some embodiments, the solder mask 103 substantially covers a top surface 101 a of a substrate 101. The solder mask 103 includes a first recessed portion 103 b surrounding the pad 102, so that the solder mask 103 is spaced from the pad 102. In some embodiments, there is an annular gap 104 between the pad 102 and the solder mask 103. The annular gap 104 surrounds the pad 102.

In some embodiments, the first recessed portion 103 b is in a circular or an elliptical shape, and the pad 102 is also in a circular or an elliptical shape. In some embodiments, the first recessed portion 103 b has a width or diameter D_(first recessed portion), and the pad 102 has a width or diameter D_(pad). In some embodiments, the diameter D_(first recessed portion) of the first recessed portion 103 b is larger than the diameter D_(pad) of the pad 102. In some embodiments, the diameter D_(first recessed portion) of the first recessed portion 103 b is about 300 um to about 350 um. In some embodiments, the diameter D_(pad) of the pad 102 is about 200 um to 300 um.

FIG. 2A is an embodiment of a semiconductor device 100. The semiconductor device 100 includes a substrate 101. In some embodiments, the substrate 101 is a printed circuit board (PCB) including some integrated circuits (IC) for electrical connection of the semiconductor components thereon. In some embodiments, the substrate 101 is in a strip shape.

In some embodiments, the semiconductor device 100 includes a pad 102 disposed on a surface 101 a of the substrate 101. The pad 102 is extended horizontally along the surface 101 a. In some embodiments, the pad 102 is a UBM pad for receiving a conductive bump including copper, tin, lead, solder or etc. The UBM pad is configured for electrically connecting the pad 102 with a circuitry internal to the substrate 101. In some embodiments, the pad 102 is disposed on the surface 101 a by electroplating. In some embodiments, the pad 102 includes a conductive material such as gold, silver, copper, nickel, tungsten, aluminum, and/or alloys thereof.

In some embodiments, the semiconductor device 100 includes a solder mask 103 disposed over the surface 101 a of the substrate 101. In some embodiments, the solder mask 103 includes a polymeric material such as liquid epoxy, polyepoxide or etc. In some embodiments, the solder mask 103 surrounds the pad 102. In some embodiments, the solder mask 103 partially covers the pad 102. An end portion of a top surface 102 a and a peripheral portion 102 b of the pad 102 are covered by the solder mask 103. The solder mask 103 is contacted with the pad 102.

In some embodiments, a central part of the top surface 102 a is exposed for receiving a bump. In some embodiments, a top surface 103 a of the solder mask 103 is at a level above the top surface 102 a of the pad 102 and over the pad 102.

In some embodiments, the solder mask 103 includes a second recessed portion 103 c. In some embodiments, the second recessed portion 103 c is above the pad 102. The pad 102 is disposed underneath the second recessed portion 103 c. In some embodiments, the second recessed portion 103 c is extended from the top surface 103 a of the solder mask 103 to the top surface 102 a of the pad 102. A bottom of the second recessed portion 103 c is interfaced to the top surface 102 a.

In some embodiments, a sidewall 103 e of the second recessed portion 103 c is disposed on the top surface 102 a of the pad 102. In some embodiments, the second recessed portion 103 c is configured for exposing the central part of the top surface 102 a of the pad 102 to receive a bump.

In some embodiments, the pad 102 is a solder mask defined (SMD) pad. The SMD pad 102 is partially covered by the solder mask 103. A periphery of the SMD pad is surrounded by the solder mask 103, so that the central part of the top surface 102 a of the SMD pad 102 for receiving the bump is defined by the solder mask 103. The central part of the top surface 102 a of the SMD pad 102 is exposed depending on a size of the second recessed portion 103 c. In some embodiments, the second recessed portion 103 c is smaller than the SMD pad 102.

FIG. 2B is a top view of an embodiment of a semiconductor device 100 as in FIG. 2A. The semiconductor device 100 includes a substrate 101, a pad 102 and a solder mask 103. In some embodiments, the solder mask 103 covers a top surface 101 a of a substrate 101 and a peripheral portion 102 b of the pad 102. The solder mask 103 includes a second recessed portion 103 c disposed above the pad 102. In some embodiments, the peripheral portion 102 b of the pad 102 is circumferentially surrounded by the solder mask 103.

In some embodiments, the second recessed portion 103 c is in a circular or an elliptical shape, and the pad 102 is also in a circular or an elliptical shape. In some embodiments, the second recessed portion 103 c has a width or diameter D_(second recessed portion), and the pad 102 has a width or diameter D_(pad). In some embodiments, the diameter D_(second) recessed portion of the second recessed portion 103 c is smaller than the diameter Dpad of the pad 102. In some embodiments, the diameter Dsecond recessed portion of the second recessed portion 103 c is about 175 um to about 250 um. In some embodiments, the diameter Dpad of the pad 102 is about 250 um to 350 um.

FIG. 3A is an embodiment of a semiconductor device 200. The semiconductor device 200 includes a substrate 101, a solder mask 103 and several pads 102 disposed on the top surface 101 a of the substrate 101. In some embodiments, the pads 102 includes several NSMD pads 102-1 and several SMD pads 102-2. The NSMD pad 102-1 has similar configuration as in FIG. 1A and 1B. The SMD pad 102-2 has similar configuration as in FIGS. 2A and 2B. In some embodiments, the solder mask 103 covers a peripheral portion 102 b of the SMD pad 102-2, while spaces away from the NSMD pad 102-1.

In some embodiments, the solder mask 103 includes several first recessed portions 103 b and several second recessed portions 103 c. The NSMD pad 102-1 is within the first recessed portion 103 b, and the SMD pad 102-2 is disposed underneath the second recessed portion 103 c.

FIG. 3B is a top view of an embodiment of a semiconductor device 200 as in FIG. 3A. The semiconductor device 200 includes a substrate 101, several NSMD pads 102-1, several SMD pads 102-2 and a solder mask 103 disposed over the top surface 101 a. In some embodiments, the solder mask 103 includes several first recessed portions 103 b and several second recessed portions 103 c, so that the NSMD pad 102-1 is spaced from the solder mask 103 in a annular gap 104 and a peripheral portion 102 b of the SMD pad 102-2 is circumferentially covered by the solder mask 103.

FIG. 4A is an embodiment of a semiconductor device 200. The semiconductor device 200 includes a substrate 101, a solder mask 103 on the substrate, several NSMD pads 102-1 and several SMD pads 102-2 disposed on the substrate 101. In some embodiments, the SMD pad 102-2 is disposed away from the corner 101 b of the substrate 101. In some embodiments, the SMD pad 102-2 is disposed at a central portion of the substrate 101.

In some embodiments, the NSMD pads 102-1 and the SMD pads 102-2 are arranged in a regular array. The NSMD pads 102-1 and the SMD pads 102-2 are disposed in several horizontal rows and several vertical columns on the substrate 101.

In some embodiments, the NSMD pad 102-1 is arranged at a predetermined location. In some embodiments, the predetermined location is at a corner 101 b of the substrate 101. The NSMD pad 102-1 is configured for receiving a bump which could electrically connects with a pad on another substrate.

In some embodiments, the NSMD pad 102-1 is arranged at the corner 101 b because the NSMD pad 102-1 allows the bump disposing on a top surface 102 a as well as a peripheral portion 102 b of the NSMD pad 102-1, so as to minimize or even prevent a development of stress concentration point around the solder mask 103. As such, disposition of the NSMD pad 102-1 at the corner 101 b of the substrate 101 provides an improved reliability of the substrate 101 with respect to drop test, board level temperature cycle, board bending, etc and minimize development of cracking and delamination of components.

In some embodiments, the solder mask 103 includes several first recessed portions 103 b and several second recessed portions 103 c. In some embodiments, the first recessed portion 103 b surrounds the NSMD pad 102-1, and the second recessed portion 103 c is disposed above the SMD pad 102-2.

In some embodiments, the first recessed portion 103 b is disposed at the predetermined location in accordance with a position of a corresponding NSMD pad 102-1. In some embodiments, the first recessed portion 103 b is disposed at the corner 101 b of the substrate 101 because the NSMD pad 102-1 is also disposed at the corner 101 b. The position of the first recessed portion 103 b corresponds to the position of the corresponding NSMD pad 102-1.

In some embodiments, the second recessed portion 103 c is disposed at a position corresponding to a position of the SMD pad 102-2. In some embodiments, the second recessed portion 103 c is disposed at the central portion of the substrate 101 because the corresponding SMD pad 102-2 is also disposed at the central portion. The position of the second recessed portion 103 c corresponds to the position of the corresponding SMD pad 102-2.

FIG. 4B is an embodiment of a semiconductor device 200. The semiconductor device 200 includes a substrate 101, a solder mask 103 on the substrate, several NSMD pads 102-1 and several SMD pads 102-2 disposed on the substrate 101. In some embodiments, the SMD pad 102-2 is disposed at a central portion of the substrate 101.

In some embodiments, the NSMD pad 102-1 is arranged at a predetermined location. In some embodiments, the predetermined location is at a corner 101 b of the substrate 101 and at a corner region adjacent to the corner 101 b. In some embodiments, the NSMD pad 102-1 neighboring with the NSMD pad 102-1 at the corner 101 b. In some embodiments, there are three NSMD pads 102-1 are disposed at the corner 101 b and the corner region.

In some embodiments, the solder mask 103 includes several first recessed portions 103 b and several second recessed portions 103 c. In some embodiments, the first recessed portion 103 b is disposed at the predetermined location in accordance with a position of a corresponding NSMD pad 102-1. In some embodiments, the first recessed portion 103 b is disposed at the corner 101 b as well as the corner region. In some embodiments, there are three first recessed portions 103 b disposed at the corner 101 b and the corner region, corresponding to the positions of the corresponding NSMD pads 102-1.

FIG. 4C is an embodiment of a semiconductor device 200. The semiconductor device 200 includes a substrate 101, a solder mask 103 on the substrate, several NSMD pads 102-1 and several SMD pads 102-2 disposed on the substrate 101. In some embodiments the NSMD pads 102-1 and the SMD pads 101-2 are arranged in an irregular array including a void region 101 c which is absent from the NSMD pad and the SMD pad.

In some embodiments, the NSMD pad 102-1 is arranged at a predetermined location. In some embodiments, the predetermined location is at a position adjacent to the void region 101 c of the substrate 101. The pad 102 adjacent to the void region 101 c is defined as an isolated pad and is disposed as a NSMD pad 102-1. The isolated pad is neighbored with less than four of the pads 102. In some embodiments, there are two isolated pads adjacent to the void region 101 c and disposed as NSMD pads 102-1.

In some embodiments, the solder mask 103 includes several first recessed portions 103 b and several second recessed portions 103 c. In some embodiments, the first recessed portion 103 b is disposed at the predetermined location in accordance with a position of a corresponding NSMD pad 102-1. In some embodiments, the first recessed portion 103 b is disposed adjacent to the void region 101 c. The first recessed portion 103 b surrounds the isolate pad adjacent to the void region 101 c. In some embodiments, there are two first recessed portions 103 b disposed adjacent to the void region 101 c, corresponding to the positions of the corresponding NSMD pads 102-1 defined as isolated pads.

In the present disclosure, a method of manufacturing a semiconductor device is also disclosed. In some embodiments, a semiconductor device is formed by a method 300. The method 300 includes a number of operations and the description and illustration are not deemed as a limitation as the sequence of the operations.

FIG. 5 is an embodiment of a method 300 of manufacturing a semiconductor device. The method 300 includes a number of operations (301, 302, 303, 304, 305, 306, 307, 308, 309).

In operation 301, a first substrate 101 is provided as in FIG. 5A. In some embodiments, the first substrate 101 is a silicon substrate for supporting several semiconductor components and carrying a circuitry within the substrate. In some embodiments, the first substrate 101 is a printed circuit board (PCB).

In operation 302, several pads 102 are disposed on a surface 101 a of the substrate 101 as in FIG. 5B. In some embodiments, the pads 102 are disposed horizontally along the surface 101 a. In some embodiments, the pad 102 is an under bump metallurgy (UBM) pad for receiving a bump. In some embodiments, the pads 102 are disposed on the surface 101 a by electroplating. In some embodiments, the pad 102 includes a conductive material such as gold, silver, copper, nickel, tungsten, aluminum, and/or alloys thereof.

In operation 303, a solder mask 103 is disposed over the surface 101 a of the substrate 101 as in FIG. 5C. The solder mask 103 covers the pads 102 and the surface 101 a. In some embodiments, the solder mask 103 includes a polymeric material such as liquid epoxy, polyepoxide or etc. In some embodiments, the solder mask 103 is disposed on the surface 101 a of the substrate 101 by silk screening, spraying, etc.

In operation 304, a position of a first recess and a position of a second recess on the solder mask are determined by various methods. In some embodiments, the position of the first recess and the position of the second recess are at predetermined positions.

In some embodiments the positions are determined by a method as in FIG. 5D. FIG. 5D is a top view of the semiconductor device 200 as in FIGS. 5A, 5B and 5C. In some embodiments, the position of the first recess 103 b and the position of the second recess 103 c are determined by defining a circle 105 with a predetermined neutral point NP and a predetermined diameter DNP. In some embodiments, the circle 105 is centered at the neutral point NP and has a diameter DNP. The neutral point NP is a center of the circle 105.

In some embodiments, the position of the first recess 103 b is determined at a position over the pad 102 outside the circle 105. In some embodiments, the pad 102 is disposed at a distance greater than a distance DNP between the neutral point NP and a circumference of the circle 105. In some embodiments, the position above the pad 102 outside the circle 105 is a corner 101 b of the substrate 101. As such, the first recess 103 b is determined at the corner 101 b and over the pad 102. In some embodiments, there are four first recesses 103 b disposed on the solder mask 103 and at the corner 101 b.

In some embodiments, the position of the second recess 103 c is determined at a position above the pad inside the circle 105. In some embodiments, the pad 102 is disposed at a distance less than a distance DNP between the neutral point NP and the circumference of the circle 105. In some embodiments, the position above the pad 102 inside the circle 105 is a central portion of the substrate 101, and thus the second recess 103 b is determined at the central portion. In some embodiments, there are thirty two second recesses 103 c disposed on the solder mask 103 and at the central portion of the substrate 101.

In some embodiments the positions of the first recess and second recess are determined by a method as in FIG. 5E. FIG. 5E is a top view of the semiconductor device 200 as in FIGS. 5A, 5B and 5C. In some embodiments, the position of the first recess 103 b and the position of the second recess 103 c are determined by defining a circle 105 with a predetermined neutral point NP and a predetermined diameter DNP. In some embodiments, the neutral point NP is a center of the circle 105.

In some embodiments, the position of the first recess 103 b is determined at a position over the pad 102 outside the circle 105. In some embodiments, the pad 102 is disposed at a distance greater than a distance DNP between the neutral point NP and a circumference of the circle 105. In some embodiments, the position above the pad 102 outside the circle 105 is adjacent to a corner 101 b of the substrate 101, and thus the first recess 103 b is determined at the position adjacent to the corner 101 b and over the pad 102. In some embodiments, there are twelve first recesses 103 b disposed on the solder mask 103 over the pads 102 and at the position adjacent to the corner 101 b.

In some embodiments, the position of the second recess 103 c is determined at a position above the pad inside the circle 105. In some embodiments, the pad 102 is disposed at a distance less than a distance DNP between the neutral point NP and the circumference of the circle 105. In some embodiments, the position above the pad 102 inside the circle 105 is a central portion of the substrate 101, and thus the second recess 103 c is determined at the central portion. In some embodiments, there are twenty four second recesses 103 c disposed on the solder mask 103 above the pads 102 and at the central portion of the substrate 101.

In some embodiments, the positions of the first recess and second recess are determined by a method as in FIG. 5F. FIG. 5F is a top view of the semiconductor device 200 as in FIGS. 5A, 5B and 5C. In some embodiments, the position of the first recess 103 b and the position of the second recess 103 c are determined according to a definition of a pad 102 as an isolated pad.

In some embodiments, the pad 102 is defined as the isolated pad if the pad 102 is adjacent to a void region 101 c of the substrate 101. In some embodiments, the pad 102 is defined as the isolated pad if the pad 102 is neighbored with less than four of the pads 102. In some embodiments, there are two isolated pads adjacent to the void region 101 c, and thus the first recess 103 b is disposed above the isolated pad. In some embodiments, the second recess 103 c is disposed above the pad 102 defined as non-isolated pad. The non-isolated pad is the pad 102 neighboring with more than four pads 102.

In some embodiments the positions of the first recess and second recess are determined by combination of the methods of FIG. 5D and 5F as a method in FIG. 5G. FIG. 5G is a top view of the semiconductor device 200 as in FIGS. 5A, 5B and 5C. In some embodiments, the position of the first recess 103 b is determined by defining a pad 102 as an isolated pad as well as defining a circle 105 with a predetermined neutral point NP and a predetermined diameter DNP. The first recess 103 b is disposed over the pad 102 as the isolated pad adjacent to a void region 101 c or outside the circle 105, while the second recess 103 c is disposed over the pad 102 as a non-isolated pad away from the void region 101 c or inside the circle 105.

In some embodiments the positions of the first recess and second recess are determined by combination of the methods of FIGS. 5E and 5F as a method in FIG. 5H. FIG. 5H is a top view of the semiconductor device 200 as in FIGS. 5A, 5B and 5C. In some embodiments, the position of the first recess 103 b is determined by defining a pad 102 as an isolated pad as well as defining a circle 105 with a predetermined neutral point NP and a predetermined diameter DNP. The first recess 103 b is disposed over the pad 102 as the isolated pad adjacent to a void region 101 c or outside the circle 105, while the second recess 103 c is disposed over the pad 102 as a non-isolated pad away from the void region 101 c or inside the circle 105

In operation 305, a portion of the solder mask 103 is removed as in FIG. 5I. In some embodiments, a portion of the solder mask 103 is removed according to the determination of the positions of the first recess 103 b and the second recess 103 c over the pad 102, with reference to the operation 304 and FIG. 5D-5H as described above.

In operation 306, the first recess 103 b of the solder mask 103 is formed as in FIG. 5I. In some embodiments, the first recess 103 b is formed over the pad 102, so that the pad 102 becomes a non-solder mask defined (NSMD) pad 102-1. The NSMD pad 102-1 is in a configuration similar to FIGS. 1A and 1B. The NSMD pad 102-1 is correspondingly within the first recess 103 b and is spaced away from the first recess 103 b in a gap 104.

In operation 307, the second recess 103 c of the solder mask 103 is formed as in FIG. 5I. In some embodiments, the second recess 103 c is formed above the pad 102, so that the pad 102 becomes a solder mask defined (SMD) pad 102-2. The SMD pad 102-2 is in a configuration similar to FIGS. 1C and 1D. The SMD pad 102-2 is correspondingly above the second recess 103 b and is partially covered by the solder mask 103.

In operation 308, a second substrate 401 is provided as in FIG. 5J. In some embodiments, the second substrate 401 is a wafer substrate including a die and a circuitry within the wafer substrate. In some embodiments, several die pads 402 are disposed on a surface 404 of the second substrate 401. The die pad 402 is configured for receiving a bump.

In operation 309, the first substrate 101 is bonded with the second substrate 401. In some embodiments, the first substrate 101 bonds with the second substrate 401 by connecting the pads 102 of the first substrate 101 correspondingly with the die pads 402 of the second substrate 401 by several bumps 403. The bumps 403 are attached with the die pads 402 and the pads 102 correspondingly, so that the circuitry within the first substrate 101 is electrically connected to the circuitry within the second substrate 401 through the pads 102, the die pads 402 and the bumps 403.

In some embodiments, a semiconductor device includes a substrate, a plurality of pads disposed over the substrate, and a solder mask disposed over the substrate. The substrate includes a pair of first edges parallel to each other, a pair of second edges orthogonal to the pair of first edges, and a center point. First vertical distances between the center point and each of the pair of first edges are the same, and second vertical distances between the center point and each of the pair of second edges are the same. The plurality of pads are arranged to form a regular array including a plurality of horizontal rows and a plurality of vertical columns. The solder mask includes four recess portions exposing an entire top surface and sidewalls of four of the pads in four corners of the regular array, and a plurality of second recess portions exposing a portion of a top surface of other pads in the regular array. A pad size of the four pads in the four corners of the regular array exposed through the first recess portions and a pad size of the other pads exposed through the second recess portions are the same.

In some embodiments, the plurality of pads include four non-solder mask defined (NSMD) pads in the four corners of the regular array and a plurality of solder mask defined (SMD) pads disposed away from the four corners of the regular array. In some embodiments, each of the four NSMD pads is adjacent to one of the SMD pads in a same horizontal row and another one of the SMD pads in a same vertical column. In some embodiments, the first vertical distances are similar to the second vertical distances. In some embodiments, the first vertical distances are different from the second vertical distances. In some embodiments, a first distance is defined as a distance between the center point and each of the four first recess portions, and the first distance is greater than at least one of the first vertical distance and the second vertical distance. In some embodiments, a second distance is defined as a distance between the center point and each of the second recess portions, and the second distance is less than the first vertical distance and the second vertical distance. In some embodiments, the first distance is greater than the second distance.

In some embodiments, a semiconductor device includes a substrate, a plurality of pads disposed over the substrate, and a solder mask disposed over the substrate. The substrate includes a first edge, a second edge orthogonal to the first edge, a corner formed by the first edge and the second edge, and a center point. A first vertical distance is defined as a distance between the center point and the first edge, a second distance is defined as a distance between the center point and the second edge. In some embodiments, the first vertical distance is greater than the second vertical distance. The plurality of pads are arranged to form a regular array including a plurality of horizontal rows and a plurality of vertical columns. In some embodiments, the plurality of pads include a corner pad disposed in a corner of the regular array and an non-corner pad disposed away from the corner of the regular array. The solder mask includes a first recess portion disposed in the corner of the substrate and exposing an entire top surface and sidewalls of the corner pad and a second recess portion exposing a portion of a top surface of the non-corner pad. In some embodiments, a pad size of the corner pad exposed through the first recess portion and a pad size of the non-corner pad exposed through the second recess portion are the same.

In some embodiments, the corner pad is an NSMD pad, and the non-corner pad is a SMD pad. In some embodiments, a first distance is defined as a distance between the center point and the first recess portion, and the first distance is greater than at least one of the first vertical distance and the second vertical distance. In some embodiments, a second distance is defined as a distance between the center point and the second recess portion, and the second distance is less than the first vertical distance and the second vertical distance. In some embodiments, the first distance is greater than the second distance.

In some embodiments, a semiconductor device includes providing a substrate, a plurality of first NSMD pads disposed over the substrate, a plurality of SMD pads disposed over the substrate, and a solder mask exposing an entire top surface and sidewalls of each of the first NSMD pads and a portion of a top surface of each of the SMD pads. The substrate includes a pair of first edges parallel to each other, a pair of second edges orthogonal to the first edges, and a center point. First distances defined as distances between the center point and each of the pair of first edges are the same, and second distances defined as distances between the center point and each of the pair of second edges are the same. A pad size of each of first NSMD pads exposed through the solder mask and a pad size of each SMD pads exposed through the solder mask are the same.

In some embodiments, the first vertical distance and the second vertical distance are different. In some embodiments, a first distance is defined as a distance between the center point and each of the first NSMD pads, and the first distance is greater than at least one of the first vertical distance and the second vertical distance. In some embodiments, a second distance is defined as a distance between the center point and each of the SMD pads, and the second distance is less than the first vertical distance and the second vertical distance. In some embodiments, the first distance is greater than the second distance. In some embodiments, the first NSMD pads and the SMD pads are arranged in an irregular array thereby the substrate includes a void region absent from the plurality of pads. In some embodiments, the semiconductor device further includes at least one second NSMD pad disposed adjacent to the void region.

The features of this invention have been sufficiently described in the above examples and descriptions. It should be understood that any modifications or changes without departing from the spirit of the invention are intended to be covered in the protection scope of the invention.

Moreover, the scope of the present application in not intended to be limited to the particular embodiments of the process, machine, manufacture, and composition of matter, means, methods and steps described in the specification. As those skilled in the art will readily appreciate from the disclosure of the present disclosure, processes, machines, manufacture, composition of matter, means, methods or steps presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein maybe utilized according to the present disclosure.

Accordingly, the appended claims are intended to include within their scope such as processes, machines, manufacture, compositions of matter, means, methods or steps. In addition, each claim constitutes a separate embodiment, and the combination of various claims and embodiments are within the scope of the invention. 

The invention claimed is:
 1. A semiconductor device, comprising: a substrate comprising a pair of first edges parallel to each other, a pair of second edges orthogonal to the pair of first edges, and a center point, wherein first vertical distances defined as distances between the center point and each of the pair of first edges are the same, and second vertical distances defined as distances between the center point and each of the pair of second edges are the same; a plurality of pads disposed over the substrate and arranged to form a regular array including a plurality of horizontal rows and a plurality of vertical columns; and a solder mask disposed over the substrate, the solder mask comprising: four first recess portions exposing an entire top surface and sidewalls of four of the pads in four corners of the regular array; and a plurality of second recess portions exposing a portion of a top surface of other pads in the regular array. wherein a pad size of the four pads in the four corners of the regular array exposed through the first recess portions and a pad size of the other pads exposed through the second recess portions are the same.
 2. The semiconductor device of claim 1, wherein the plurality of pads comprise four non-solder mask defined (NSMD) pads in the four corners of the regular array and a plurality of solder mask defined (SMD) pads disposed away from the four corners of the regular array.
 3. The semiconductor of claim 2, wherein each of the four NSMD pads is adjacent to one of the SMD pads in a same horizontal row and another one of the SMD pads in a same vertical column.
 4. The semiconductor device of claim 1, wherein the first vertical distances are similar to the second vertical distances.
 5. The semiconductor device of claim 1, wherein the first vertical distances are different from the second vertical distances.
 6. The semiconductor device of claim 1, wherein a first distance is defined as a distance between the center point and each of the four first recess portions, and the first distance is greater than at least one of the first vertical distance and the second vertical distance.
 7. The semiconductor device of claim 6, wherein a second distance is defined as a distance between the center point and each of the second recess portions, and the second distance is less than the first vertical distance and the second vertical distance.
 8. The semiconductor device of claim 7, wherein the first distance is greater than the second distance.
 9. A semiconductor device, comprising: a substrate comprising a first edge, a second edge orthogonal to the first edge, a corner formed by the first edge and the second edge, and a center point, wherein a first vertical distance is defined as a distance between the center point and the first edge, a second vertical distance is defined as a distance between the center point and the second edge, and the first vertical distance is greater than the second vertical distance; a plurality of pads disposed over the substrate and arranged to form a regular array including a plurality of horizontal rows and a plurality of vertical columns, wherein the plurality of pads comprises: a corner pad disposed in a corner of the regular array; and an non-corner pad disposed away from the corner of the regular array; and a solder mask disposed over the substrate, the solder mask comprising: a first recess portion disposed in the corner of the substrate and exposing an entire top surface and sidewalls of the corner pad; and a second recess portion exposing a portion of a top surface of the non-corner pad, wherein a pad size of the corner pad exposed through the first recess portion and a pad size of the non-corner pad exposed through the second recess portion are the same.
 10. The semiconductor device of claim 9, wherein the corner pad is an non-solder mask defined (NSMD) pad and the non-corner pad is a (SMD) pad.
 11. The semiconductor device of claim 9, wherein a first distance is defined as a distance between the center point and the first recess portion, and the first distance is greater than at least one of the first vertical distance and the second vertical distance.
 12. The semiconductor device of claim 11, wherein a second distance is defined as a distance between the center point and the second recess portion, and the second distance is less than the first vertical distance and the second vertical distance.
 13. The semiconductor device of claim 12, wherein the first distance is greater than the second distance.
 14. A semiconductor device, comprising: a substrate comprising a pair of first edges parallel to each other, a pair of second edges orthogonal to the first edges, and a center point, wherein first vertical distances defined as distances between the center point and each of the pair of first edges are the same, and second vertical distances defined as distance between the center point and each of the pair of second edges are the same; a plurality of first non-solder mask defined (NSMD) pads disposed over the substrate; and a plurality of solder mask defined (SMD) pads disposed over the substrate; a solder mask exposing an entire top surface and sidewalls of each of the first NSMD pads and a portion of a top surface of each of the SMD pads, wherein a pad size of each first NSMD pads exposed through the solder mask and a pad size of each SMD pads exposed through the solder mask are the same.
 15. The semiconductor device of claim 14, wherein the first vertical distance and the second vertical distance are different.
 16. The semiconductor device of claim 14, wherein a first distance is defined as a distance between the center point and each of the first NSMD pads, and the first distance is greater than at least one of the first vertical distance and the second vertical distance.
 17. The semiconductor device of claim 16, wherein a second distance is defined as a distance between the center point and each of the SMD pads, and the second distance is less than the first vertical distance and the second distance.
 18. The semiconductor device of claim 17, wherein the first distance is greater than the second distance.
 19. The semiconductor device of claim 14, wherein the first NSMD pads and the SMD pads are arranged in an irregular array thereby the substrate includes a void region absent from the plurality of pads.
 20. The semiconductor device of claim 19, further comprising at least one second NSMD pad disposed adjacent to the void region. 